g through the back pages of his notes.
"Got Plato down cold somewhere,--oh, here. He never caught on to the
subjective, any more than the other Greek bucks. Go on to the next
chappie."

"If you gentlemen have mastered the--the Grreek bucks," observed the
instructor, with sleek intonation, "we--"

"Yep," said the second tennis boy, running a rapid judicial eye over his
back notes, "you've put us on to their curves enough. Go on."

The instructor turned a few pages forward in the thick book of his own
neat type-written notes and then resumed,--

"The self-knowledge of matter in motion."

"Skip it," put in the first tennis boy.

"We went to those lectures ourselves," explained the second, whirling
through another dishevelled notebook. "Oh, yes. Hobbes and his gang.
There is only one substance, matter, but it doesn't strictly exist.
Bodies exist. We've got Hobbes. Go on."

The instructor went forward a few pages more in his exhaustive volume.
He had attended all the lectures but three throughout the year, taking
them down in short-hand. Laryngitis had kept him from those three, to
which however, he had sent a stenographic friend so that the chain
was unbroken. He now took up the next philosopher on the list; but his
smooth discourse was, after a short while, rudely shaken. It was the
second tennis boy questioning severely the doctrines imparted.

"So he says color is all your eye, and shape isn't? and substance
isn't?"

"Do you mean he claims," said the first boy, equally resentful, "that if
we were all extinguished the world would still be here, only there'd be
no difference between blue and pink, for instance?"

"The reason is clear," responded the tutor, blandly. He adjusted his
eyeglasses, placed their elastic cord behind his ear, and referred to
his notes. "It is human sight that distinguishes between colors. If
human sight be eliminated from the universe, nothing remains to make the
distinction, and consequently there will be none. Thus also is it with
sounds. If the universe contains no ear to hear the sound, the sound has
no existence."

"Why?" said both the tennis boys at once.

The tutor smiled. "Is it not clear," said he, "that there can be no
sound if it is not heard!"

"No," they both returned, "not in the least clear."

"It's clear enough what he's driving at of course," pursued the first
boy. "Until the waves of sound or light or what not hit us through our
senses, our brains don't experienc